content_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center_horizontal"
    android:background="@drawable/bckg"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.example.nidhi.nurseryapp.in.example.nidhi.nurseryapp.MainActivity"
    tools:showIn="@layout/app_bar_main">
   <ImageView
       android:id="@+id/image"
       android:background="@color/optionsimagebackgroundcolor"
       android:src="@drawable/ic_abc"
       android:onClick="next"
       android:layout_marginBottom="50dp"
       android:padding="16dp"
       android:layout_width="130dp"
       android:layout_height="130dp"
       android:layout_marginTop="50dp"/>

    <ImageView
        android:id="@+id/image2"
        android:padding="16dp"
        android:background="@color/optionsimagebackgroundcolor"
        android:layout_width="130dp"
        android:layout_height="120dp"
        android:onClick="next"
        android:src="@drawable/ic_assignment_black_24dp" />


  </LinearLayout>